Add github action

[kristinmarshall-NOAA]

@kellijohnson-NOAA suggested it would be a good idea to add a github action that compiles the document automatically so users don't have to download all the code and compile it themselves, and/or we don't have to regularly post a compiled version

[iantaylor-NOAA]

@kristinmarshall-NOAA, revisiting this based on our discussion a few minutes ago, I think that all that's needed to get the quarto doc compiling and posted to github for public access are to run these commands:

install.packages("remotes") # probably you already have this
remotes::install_github("nmfs-fish-tools/ghactions4r") # install package maintained by Kathryn Doering
ghactions4r::use_build_deploy_bookdown()

Those commands create the .yml files that github will use to run the github action and push the document to the github site.
You may also have to change the settings to tell it to deploy the pages from a "gh-actions" branch which hasn't yet been created (but will be by the github action). See screenshot below. You can look at this site for example settings (which you should have access to): https://github.com/pfmc-assessments/pfmc_assessment_handbook/settings/pages.

I'm happy to work on this, but if you want to see how the setup process works, please go for it.

Settings page that maybe needs changing (or at least looking at), once the github action runs and creates the "gh-actions" branch: